researchers hope to use the technology to produce human kidneys. >>> according to a new government report, women at high risk of developing breast cancer could benefit from preventive medicines. we are introduced to one woman who started using the drug tamoxifen to lower her chances of getting the disease. >> reporter: breast cancer runs in nadine's body. after doctors removed an abnormal lump, she went on a drug to reduce breast cancer by 50%. >> i felt like i was a sitting duck. i wasn't really doing anything pro actively about all of the family history of breast cancer. >> reporter: according to new recommendations from the u.s. preventive services task force, women should find out from their doctors if they have a high risk of getting breast cancer. >> for example, age, race, ethnicity, the age at which the woman delivered or had her first live born child, family history. >> reporter: if they are at high risk, they should discuss with their doctor whether drugs like tamoxifen are right for them. both carry serious side effects. >> hot flashes and menopausal symptoms. increased risk fo